--- jsr166/src/jsr166y/ForkJoinPool.java	2009/07/20 22:26:03	1.9
+++ jsr166/src/jsr166y/ForkJoinPool.java	2009/07/27 20:57:44	1.28
@@ -5,12 +5,19 @@
  */
 
 package jsr166y;
-import java.util.*;
+
 import java.util.concurrent.*;
-import java.util.concurrent.locks.*;
-import java.util.concurrent.atomic.*;
-import sun.misc.Unsafe;
-import java.lang.reflect.*;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.LockSupport;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
 
 /**
  * An {@link ExecutorService} for running {@link ForkJoinTask}s.  A
@@ -56,6 +63,9 @@ import java.lang.reflect.*;
  * maximum number of running threads to 32767. Attempts to create
  * pools with greater than the maximum result in
  * IllegalArgumentExceptions.
+ *
+ * @since 1.7
+ * @author Doug Lea
  */
 public class ForkJoinPool extends AbstractExecutorService {
 
@@ -81,13 +91,13 @@ public class ForkJoinPool extends Abstra
          * Returns a new worker thread operating in the given pool.
          *
          * @param pool the pool this thread works in
-         * @throws NullPointerException if pool is null;
+         * @throws NullPointerException if pool is null
          */
         public ForkJoinWorkerThread newThread(ForkJoinPool pool);
     }
 
     /**
-     * Default ForkJoinWorkerThreadFactory implementation, creates a
+     * Default ForkJoinWorkerThreadFactory implementation; creates a
      * new ForkJoinWorkerThread.
      */
     static class  DefaultForkJoinWorkerThreadFactory
@@ -181,7 +191,7 @@ public class ForkJoinPool extends Abstra
     private final LinkedTransferQueue<ForkJoinTask<?>> submissionQueue;
 
     /**
-     * Head of Treiber stack for barrier sync. See below for explanation
+     * Head of Treiber stack for barrier sync. See below for explanation.
      */
     private volatile WaitQueueNode syncStack;
 
@@ -216,8 +226,8 @@ public class ForkJoinPool extends Abstra
      * threads, packed into one int to ensure consistent snapshot when
      * making decisions about creating and suspending spare
      * threads. Updated only by CAS.  Note: CASes in
-     * updateRunningCount and preJoin running active count is in low
-     * word, so need to be modified if this changes
+     * updateRunningCount and preJoin assume that running active count
+     * is in low word, so need to be modified if this changes.
      */
     private volatile int workerCounts;
 
@@ -226,26 +236,28 @@ public class ForkJoinPool extends Abstra
     private static int workerCountsFor(int t, int r) { return (t << 16) + r; }
 
     /**
-     * Add delta (which may be negative) to running count.  This must
+     * Adds delta (which may be negative) to running count.  This must
      * be called before (with negative arg) and after (with positive)
-     * any managed synchronization (i.e., mainly, joins)
+     * any managed synchronization (i.e., mainly, joins).
+     *
      * @param delta the number to add
      */
     final void updateRunningCount(int delta) {
         int s;
-        do;while (!casWorkerCounts(s = workerCounts, s + delta));
+        do {} while (!casWorkerCounts(s = workerCounts, s + delta));
     }
 
     /**
-     * Add delta (which may be negative) to both total and running
+     * Adds delta (which may be negative) to both total and running
      * count.  This must be called upon creation and termination of
      * worker threads.
+     *
      * @param delta the number to add
      */
     private void updateWorkerCount(int delta) {
         int d = delta + (delta << 16); // add to both lo and hi parts
         int s;
-        do;while (!casWorkerCounts(s = workerCounts, s + d));
+        do {} while (!casWorkerCounts(s = workerCounts, s + d));
     }
 
     /**
@@ -271,9 +283,10 @@ public class ForkJoinPool extends Abstra
     private static int runControlFor(int r, int a)   { return (r << 16) + a; }
 
     /**
-     * Try incrementing active count; fail on contention. Called by
-     * workers before/during executing tasks.
-     * @return true on success;
+     * Tries incrementing active count; fails on contention.
+     * Called by workers before/during executing tasks.
+     *
+     * @return true on success
      */
     final boolean tryIncrementActiveCount() {
         int c = runControl;
@@ -281,9 +294,10 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Try decrementing active count; fail on contention.
-     * Possibly trigger termination on success
+     * Tries decrementing active count; fails on contention.
+     * Possibly triggers termination on success.
      * Called by workers when they can't find tasks.
+     *
      * @return true on success
      */
     final boolean tryDecrementActiveCount() {
@@ -297,12 +311,13 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Return true if argument represents zero active count and
-     * nonzero runstate, which is the triggering condition for
+     * Returns {@code true} if argument represents zero active count
+     * and nonzero runstate, which is the triggering condition for
      * terminating on shutdown.
      */
     private static boolean canTerminateOnShutdown(int c) {
-        return ((c & -c) >>> 16) != 0; // i.e. least bit is nonzero runState bit
+        // i.e. least bit is nonzero runState bit
+        return ((c & -c) >>> 16) != 0;
     }
 
     /**
@@ -328,12 +343,13 @@ public class ForkJoinPool extends Abstra
 
     /**
      * Creates a ForkJoinPool with a pool size equal to the number of
-     * processors available on the system and using the default
-     * ForkJoinWorkerThreadFactory,
+     * processors available on the system, using the default
+     * ForkJoinWorkerThreadFactory.
+     *
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public ForkJoinPool() {
         this(Runtime.getRuntime().availableProcessors(),
@@ -342,14 +358,15 @@ public class ForkJoinPool extends Abstra
 
     /**
      * Creates a ForkJoinPool with the indicated parallelism level
-     * threads, and using the default ForkJoinWorkerThreadFactory,
+     * threads and using the default ForkJoinWorkerThreadFactory.
+     *
      * @param parallelism the number of worker threads
      * @throws IllegalArgumentException if parallelism less than or
      * equal to zero
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public ForkJoinPool(int parallelism) {
         this(parallelism, defaultForkJoinWorkerThreadFactory);
@@ -358,13 +375,14 @@ public class ForkJoinPool extends Abstra
     /**
      * Creates a ForkJoinPool with parallelism equal to the number of
      * processors available on the system and using the given
-     * ForkJoinWorkerThreadFactory,
+     * ForkJoinWorkerThreadFactory.
+     *
      * @param factory the factory for creating new threads
      * @throws NullPointerException if factory is null
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public ForkJoinPool(ForkJoinWorkerThreadFactory factory) {
         this(Runtime.getRuntime().availableProcessors(), factory);
@@ -376,12 +394,12 @@ public class ForkJoinPool extends Abstra
      * @param parallelism the targeted number of worker threads
      * @param factory the factory for creating new threads
      * @throws IllegalArgumentException if parallelism less than or
-     * equal to zero, or greater than implementation limit.
+     * equal to zero, or greater than implementation limit
      * @throws NullPointerException if factory is null
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public ForkJoinPool(int parallelism, ForkJoinWorkerThreadFactory factory) {
         if (parallelism <= 0 || parallelism > MAX_THREADS)
@@ -402,7 +420,8 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Create new worker using factory.
+     * Creates a new worker thread using factory.
+     *
      * @param index the index to assign worker
      * @return new worker, or null of factory failed
      */
@@ -421,16 +440,18 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Return a good size for worker array given pool size.
+     * Returns a good size for worker array given pool size.
      * Currently requires size to be a power of two.
      */
-    private static int arraySizeFor(int ps) {
-        return ps <= 1? 1 : (1 << (32 - Integer.numberOfLeadingZeros(ps-1)));
+    private static int arraySizeFor(int poolSize) {
+        return (poolSize <= 1) ? 1 :
+            (1 << (32 - Integer.numberOfLeadingZeros(poolSize-1)));
     }
 
     /**
-     * Create or resize array if necessary to hold newLength.
-     * Call only under exclusion or lock
+     * Creates or resizes array if necessary to hold newLength.
+     * Call only under exclusion.
+     *
      * @return the array
      */
     private ForkJoinWorkerThread[] ensureWorkerArrayCapacity(int newLength) {
@@ -444,7 +465,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Try to shrink workers into smaller array after one or more terminate
+     * Tries to shrink workers into smaller array after one or more terminate.
      */
     private void tryShrinkWorkerArray() {
         ForkJoinWorkerThread[] ws = workers;
@@ -460,7 +481,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Initialize workers if necessary
+     * Initializes workers if necessary.
      */
     final void ensureWorkerInitialization() {
         ForkJoinWorkerThread[] ws = workers;
@@ -527,6 +548,8 @@ public class ForkJoinPool extends Abstra
      * Common code for execute, invoke and submit
      */
     private <T> void doSubmit(ForkJoinTask<T> task) {
+        if (task == null)
+            throw new NullPointerException();
         if (isShutdown())
             throw new RejectedExecutionException();
         if (workers == null)
@@ -536,7 +559,8 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Performs the given task; returning its result upon completion
+     * Performs the given task, returning its result upon completion.
+     *
      * @param task the task
      * @return the task's result
      * @throws NullPointerException if task is null
@@ -549,6 +573,7 @@ public class ForkJoinPool extends Abstra
 
     /**
      * Arranges for (asynchronous) execution of the given task.
+     *
      * @param task the task
      * @throws NullPointerException if task is null
      * @throws RejectedExecutionException if pool is shut down
@@ -560,7 +585,12 @@ public class ForkJoinPool extends Abstra
     // AbstractExecutorService methods
 
     public void execute(Runnable task) {
-        doSubmit(new AdaptedRunnable<Void>(task, null));
+        ForkJoinTask<?> job;
+        if (task instanceof ForkJoinTask<?>) // avoid re-wrap
+            job = (ForkJoinTask<?>) task;
+        else
+            job = new AdaptedRunnable<Void>(task, null);
+        doSubmit(job);
     }
 
     public <T> ForkJoinTask<T> submit(Callable<T> task) {
@@ -576,14 +606,32 @@ public class ForkJoinPool extends Abstra
     }
 
     public ForkJoinTask<?> submit(Runnable task) {
-        ForkJoinTask<Void> job = new AdaptedRunnable<Void>(task, null);
+        ForkJoinTask<?> job;
+        if (task instanceof ForkJoinTask<?>) // avoid re-wrap
+            job = (ForkJoinTask<?>) task;
+        else
+            job = new AdaptedRunnable<Void>(task, null);
         doSubmit(job);
         return job;
     }
 
     /**
+     * Submits a ForkJoinTask for execution.
+     *
+     * @param task the task to submit
+     * @return the task
+     * @throws RejectedExecutionException if the task cannot be
+     *         scheduled for execution
+     * @throws NullPointerException if the task is null
+     */
+    public <T> ForkJoinTask<T> submit(ForkJoinTask<T> task) {
+        doSubmit(task);
+        return task;
+    }
+
+    /**
      * Adaptor for Runnables. This implements RunnableFuture
-     * to be compliant with AbstractExecutorService constraints
+     * to be compliant with AbstractExecutorService constraints.
      */
     static final class AdaptedRunnable<T> extends ForkJoinTask<T>
         implements RunnableFuture<T> {
@@ -603,6 +651,7 @@ public class ForkJoinPool extends Abstra
             return true;
         }
         public void run() { invoke(); }
+        private static final long serialVersionUID = 5232453952276885070L;
     }
 
     /**
@@ -631,29 +680,35 @@ public class ForkJoinPool extends Abstra
             }
         }
         public void run() { invoke(); }
+        private static final long serialVersionUID = 2838392045355241008L;
     }
 
     public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) {
-        ArrayList<ForkJoinTask<T>> ts =
+        ArrayList<ForkJoinTask<T>> forkJoinTasks =
             new ArrayList<ForkJoinTask<T>>(tasks.size());
-        for (Callable<T> c : tasks)
-            ts.add(new AdaptedCallable<T>(c));
-        invoke(new InvokeAll<T>(ts));
-        return (List<Future<T>>)(List)ts;
+        for (Callable<T> task : tasks)
+            forkJoinTasks.add(new AdaptedCallable<T>(task));
+        invoke(new InvokeAll<T>(forkJoinTasks));
+
+        @SuppressWarnings({"unchecked", "rawtypes"})
+        List<Future<T>> futures = (List<Future<T>>) (List) forkJoinTasks;
+        return futures;
     }
 
     static final class InvokeAll<T> extends RecursiveAction {
         final ArrayList<ForkJoinTask<T>> tasks;
         InvokeAll(ArrayList<ForkJoinTask<T>> tasks) { this.tasks = tasks; }
         public void compute() {
-            try { invokeAll(tasks); } catch(Exception ignore) {}
+            try { invokeAll(tasks); }
+            catch (Exception ignore) {}
         }
+        private static final long serialVersionUID = -7914297376763021607L;
     }
 
     // Configuration and status settings and queries
 
     /**
-     * Returns the factory used for constructing new workers
+     * Returns the factory used for constructing new workers.
      *
      * @return the factory used for constructing new workers
      */
@@ -664,7 +719,8 @@ public class ForkJoinPool extends Abstra
     /**
      * Returns the handler for internal worker threads that terminate
      * due to unrecoverable errors encountered while executing tasks.
-     * @return the handler, or null if none
+     *
+     * @return the handler, or {@code null} if none
      */
     public Thread.UncaughtExceptionHandler getUncaughtExceptionHandler() {
         Thread.UncaughtExceptionHandler h;
@@ -685,11 +741,11 @@ public class ForkJoinPool extends Abstra
      * as handler.
      *
      * @param h the new handler
-     * @return the old handler, or null if none
+     * @return the old handler, or {@code null} if none
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public Thread.UncaughtExceptionHandler
         setUncaughtExceptionHandler(Thread.UncaughtExceptionHandler h) {
@@ -717,13 +773,14 @@ public class ForkJoinPool extends Abstra
 
     /**
      * Sets the target parallelism level of this pool.
+     *
      * @param parallelism the target parallelism
      * @throws IllegalArgumentException if parallelism less than or
-     * equal to zero or greater than maximum size bounds.
+     * equal to zero or greater than maximum size bounds
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public void setParallelism(int parallelism) {
         checkPermission();
@@ -770,6 +827,7 @@ public class ForkJoinPool extends Abstra
     /**
      * Returns the maximum number of threads allowed to exist in the
      * pool, even if there are insufficient unblocked running threads.
+     *
      * @return the maximum
      */
     public int getMaximumPoolSize() {
@@ -781,8 +839,9 @@ public class ForkJoinPool extends Abstra
      * pool, even if there are insufficient unblocked running threads.
      * Setting this value has no effect on current pool size. It
      * controls construction of new threads.
+     *
      * @throws IllegalArgumentException if negative or greater then
-     * internal implementation limit.
+     * internal implementation limit
      */
     public void setMaximumPoolSize(int newMax) {
         if (newMax < 0 || newMax > MAX_THREADS)
@@ -792,11 +851,11 @@ public class ForkJoinPool extends Abstra
 
 
     /**
-     * Returns true if this pool dynamically maintains its target
-     * parallelism level. If false, new threads are added only to
-     * avoid possible starvation.
-     * This setting is by default true;
-     * @return true if maintains parallelism
+     * Returns {@code true} if this pool dynamically maintains its
+     * target parallelism level. If false, new threads are added only
+     * to avoid possible starvation.  This setting is by default true.
+     *
+     * @return {@code true} if maintains parallelism
      */
     public boolean getMaintainsParallelism() {
         return maintainsParallelism;
@@ -806,7 +865,8 @@ public class ForkJoinPool extends Abstra
      * Sets whether this pool dynamically maintains its target
      * parallelism level. If false, new threads are added only to
      * avoid possible starvation.
-     * @param enable true to maintains parallelism
+     *
+     * @param enable {@code true} to maintain parallelism
      */
     public void setMaintainsParallelism(boolean enable) {
         maintainsParallelism = enable;
@@ -822,7 +882,7 @@ public class ForkJoinPool extends Abstra
      * invocations at other times may be unpredictable.
      *
      * @param async if true, use locally FIFO scheduling
-     * @return the previous mode.
+     * @return the previous mode
      */
     public boolean setAsyncMode(boolean async) {
         boolean oldMode = locallyFifo;
@@ -839,10 +899,10 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Returns true if this pool uses local first-in-first-out
+     * Returns {@code true} if this pool uses local first-in-first-out
      * scheduling mode for forked tasks that are never joined.
      *
-     * @return true if this pool uses async mode.
+     * @return {@code true} if this pool uses async mode
      */
     public boolean getAsyncMode() {
         return locallyFifo;
@@ -863,7 +923,8 @@ public class ForkJoinPool extends Abstra
      * Returns an estimate of the number of threads that are currently
      * stealing or executing tasks. This method may overestimate the
      * number of active threads.
-     * @return the number of active threads.
+     *
+     * @return the number of active threads
      */
     public int getActiveThreadCount() {
         return activeCountOf(runControl);
@@ -873,22 +934,24 @@ public class ForkJoinPool extends Abstra
      * Returns an estimate of the number of threads that are currently
      * idle waiting for tasks. This method may underestimate the
      * number of idle threads.
-     * @return the number of idle threads.
+     *
+     * @return the number of idle threads
      */
     final int getIdleThreadCount() {
         int c = runningCountOf(workerCounts) - activeCountOf(runControl);
-        return (c <= 0)? 0 : c;
+        return (c <= 0) ? 0 : c;
     }
 
     /**
-     * Returns true if all worker threads are currently idle. An idle
-     * worker is one that cannot obtain a task to execute because none
-     * are available to steal from other threads, and there are no
-     * pending submissions to the pool. This method is conservative:
-     * It might not return true immediately upon idleness of all
-     * threads, but will eventually become true if threads remain
-     * inactive.
-     * @return true if all threads are currently idle
+     * Returns {@code true} if all worker threads are currently idle.
+     * An idle worker is one that cannot obtain a task to execute
+     * because none are available to steal from other threads, and
+     * there are no pending submissions to the pool. This method is
+     * conservative; it might not return {@code true} immediately upon
+     * idleness of all threads, but will eventually become true if
+     * threads remain inactive.
+     *
+     * @return {@code true} if all threads are currently idle
      */
     public boolean isQuiescent() {
         return activeCountOf(runControl) == 0;
@@ -899,18 +962,19 @@ public class ForkJoinPool extends Abstra
      * one thread's work queue by another. The reported value
      * underestimates the actual total number of steals when the pool
      * is not quiescent. This value may be useful for monitoring and
-     * tuning fork/join programs: In general, steal counts should be
+     * tuning fork/join programs: in general, steal counts should be
      * high enough to keep threads busy, but low enough to avoid
      * overhead and contention across threads.
-     * @return the number of steals.
+     *
+     * @return the number of steals
      */
     public long getStealCount() {
         return stealCount.get();
     }
 
     /**
-     * Accumulate steal count from a worker. Call only
-     * when worker known to be idle.
+     * Accumulates steal count from a worker.
+     * Call only when worker known to be idle.
      */
     private void updateStealCount(ForkJoinWorkerThread w) {
         int sc = w.getAndClearStealCount();
@@ -925,7 +989,8 @@ public class ForkJoinPool extends Abstra
      * an approximation, obtained by iterating across all threads in
      * the pool. This method may be useful for tuning task
      * granularities.
-     * @return the number of queued tasks.
+     *
+     * @return the number of queued tasks
      */
     public long getQueuedTaskCount() {
         long count = 0;
@@ -944,16 +1009,18 @@ public class ForkJoinPool extends Abstra
      * Returns an estimate of the number tasks submitted to this pool
      * that have not yet begun executing. This method takes time
      * proportional to the number of submissions.
-     * @return the number of queued submissions.
+     *
+     * @return the number of queued submissions
      */
     public int getQueuedSubmissionCount() {
         return submissionQueue.size();
     }
 
     /**
-     * Returns true if there are any tasks submitted to this pool
-     * that have not yet begun executing.
-     * @return {@code true} if there are any queued submissions.
+     * Returns {@code true} if there are any tasks submitted to this
+     * pool that have not yet begun executing.
+     *
+     * @return {@code true} if there are any queued submissions
      */
     public boolean hasQueuedSubmissions() {
         return !submissionQueue.isEmpty();
@@ -963,7 +1030,8 @@ public class ForkJoinPool extends Abstra
      * Removes and returns the next unexecuted submission if one is
      * available.  This method may be useful in extensions to this
      * class that re-assign work in systems with multiple pools.
-     * @return the next submission, or null if none
+     *
+     * @return the next submission, or {@code null} if none
      */
     protected ForkJoinTask<?> pollSubmission() {
         return submissionQueue.poll();
@@ -982,6 +1050,7 @@ public class ForkJoinPool extends Abstra
      * exception is thrown.  The behavior of this operation is
      * undefined if the specified collection is modified while the
      * operation is in progress.
+     *
      * @param c the collection to transfer elements into
      * @return the number of elements transferred
      */
@@ -1042,10 +1111,11 @@ public class ForkJoinPool extends Abstra
      * Invocation has no additional effect if already shut down.
      * Tasks that are in the process of being submitted concurrently
      * during the course of this method may or may not be rejected.
+     *
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public void shutdown() {
         checkPermission();
@@ -1063,11 +1133,12 @@ public class ForkJoinPool extends Abstra
      * upon termination, so always returns an empty list. However, you
      * can use method {@code drainTasksTo} before invoking this
      * method to transfer unexecuted tasks to another collection.
+     *
      * @return an empty list
      * @throws SecurityException if a security manager exists and
      *         the caller is not permitted to modify threads
      *         because it does not hold {@link
-     *         java.lang.RuntimePermission}{@code ("modifyThread")},
+     *         java.lang.RuntimePermission}{@code ("modifyThread")}
      */
     public List<Runnable> shutdownNow() {
         checkPermission();
@@ -1135,9 +1206,10 @@ public class ForkJoinPool extends Abstra
     // Shutdown and termination support
 
     /**
-     * Callback from terminating worker. Null out the corresponding
-     * workers slot, and if terminating, try to terminate, else try to
-     * shrink workers array.
+     * Callback from terminating worker. Nulls out the corresponding
+     * workers slot, and if terminating, tries to terminate; else
+     * tries to shrink workers array.
+     *
      * @param w the worker
      */
     final void workerTerminated(ForkJoinWorkerThread w) {
@@ -1168,7 +1240,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Initiate termination.
+     * Initiates termination.
      */
     private void terminate() {
         if (transitionRunStateTo(TERMINATING)) {
@@ -1183,7 +1255,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Possibly terminate when on shutdown state
+     * Possibly terminates when on shutdown state.
      */
     private void terminateOnShutdown() {
         if (!hasQueuedSubmissions() && canTerminateOnShutdown(runControl))
@@ -1191,7 +1263,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Clear out and cancel submissions
+     * Clears out and cancels submissions.
      */
     private void cancelQueuedSubmissions() {
         ForkJoinTask<?> task;
@@ -1200,7 +1272,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Clean out worker queues.
+     * Cleans out worker queues.
      */
     private void cancelQueuedWorkerTasks() {
         final ReentrantLock lock = this.workerLock;
@@ -1220,8 +1292,8 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Set each worker's status to terminating. Requires lock to avoid
-     * conflicts with add/remove
+     * Sets each worker's status to terminating. Requires lock to avoid
+     * conflicts with add/remove.
      */
     private void stopAllWorkers() {
         final ReentrantLock lock = this.workerLock;
@@ -1241,7 +1313,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Interrupt all unterminated workers.  This is not required for
+     * Interrupts all unterminated workers.  This is not required for
      * sake of internal control, but may help unstick user code during
      * shutdown.
      */
@@ -1311,7 +1383,7 @@ public class ForkJoinPool extends Abstra
         }
 
         /**
-         * Wake up waiter, returning false if known to already
+         * Wakes up waiter, returning false if known to already
          */
         boolean signal() {
             ForkJoinWorkerThread t = thread;
@@ -1323,7 +1395,7 @@ public class ForkJoinPool extends Abstra
         }
 
         /**
-         * Await release on sync
+         * Awaits release on sync.
          */
         void awaitSyncRelease(ForkJoinPool p) {
             while (thread != null && !p.syncIsReleasable(this))
@@ -1331,7 +1403,7 @@ public class ForkJoinPool extends Abstra
         }
 
         /**
-         * Await resumption as spare
+         * Awaits resumption as spare.
          */
         void awaitSpareRelease() {
             while (thread != null) {
@@ -1345,6 +1417,7 @@ public class ForkJoinPool extends Abstra
      * Ensures that no thread is waiting for count to advance from the
      * current value of eventCount read on entry to this method, by
      * releasing waiting threads if necessary.
+     *
      * @return the count
      */
     final long ensureSync() {
@@ -1366,12 +1439,12 @@ public class ForkJoinPool extends Abstra
      */
     private void signalIdleWorkers() {
         long c;
-        do;while (!casEventCount(c = eventCount, c+1));
+        do {} while (!casEventCount(c = eventCount, c+1));
         ensureSync();
     }
 
     /**
-     * Signal threads waiting to poll a task. Because method sync
+     * Signals threads waiting to poll a task. Because method sync
      * rechecks availability, it is OK to only proceed if queue
      * appears to be non-empty, and OK to skip under contention to
      * increment count (since some other thread succeeded).
@@ -1390,6 +1463,7 @@ public class ForkJoinPool extends Abstra
      * Waits until event count advances from last value held by
      * caller, or if excess threads, caller is resumed as spare, or
      * caller or pool is terminating. Updates caller's event on exit.
+     *
      * @param w the calling worker thread
      */
     final void sync(ForkJoinWorkerThread w) {
@@ -1417,14 +1491,15 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Returns true if worker waiting on sync can proceed:
+     * Returns {@code true} if worker waiting on sync can proceed:
      *  - on signal (thread == null)
      *  - on event count advance (winning race to notify vs signaller)
-     *  - on Interrupt
+     *  - on interrupt
      *  - if the first queued node, we find work available
      * If node was not signalled and event count not advanced on exit,
      * then we also help advance event count.
-     * @return true if node can be released
+     *
+     * @return {@code true} if node can be released
      */
     final boolean syncIsReleasable(WaitQueueNode node) {
         long prev = node.count;
@@ -1443,8 +1518,8 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Returns true if a new sync event occurred since last call to
-     * sync or this method, if so, updating caller's count.
+     * Returns {@code true} if a new sync event occurred since last
+     * call to sync or this method, if so, updating caller's count.
      */
     final boolean hasNewSyncEvent(ForkJoinWorkerThread w) {
         long lc = w.lastEventCount;
@@ -1458,13 +1533,13 @@ public class ForkJoinPool extends Abstra
     //  Parallelism maintenance
 
     /**
-     * Decrement running count; if too low, add spare.
+     * Decrements running count; if too low, adds spare.
      *
      * Conceptually, all we need to do here is add or resume a
      * spare thread when one is about to block (and remove or
      * suspend it later when unblocked -- see suspendIfSpare).
      * However, implementing this idea requires coping with
-     * several problems: We have imperfect information about the
+     * several problems: we have imperfect information about the
      * states of threads. Some count updates can and usually do
      * lag run state changes, despite arrangements to keep them
      * accurate (for example, when possible, updating counts
@@ -1487,12 +1562,14 @@ public class ForkJoinPool extends Abstra
      * target counts, else create only to avoid starvation
      * @return true if joinMe known to be done
      */
-    final boolean preJoin(ForkJoinTask<?> joinMe, boolean maintainParallelism) {
+    final boolean preJoin(ForkJoinTask<?> joinMe,
+                          boolean maintainParallelism) {
         maintainParallelism &= maintainsParallelism; // overrride
         boolean dec = false;  // true when running count decremented
         while (spareStack == null || !tryResumeSpare(dec)) {
             int counts = workerCounts;
-            if (dec || (dec = casWorkerCounts(counts, --counts))) { // CAS cheat
+            if (dec || (dec = casWorkerCounts(counts, --counts))) {
+                // CAS cheat
                 if (!needSpare(counts, maintainParallelism))
                     break;
                 if (joinMe.status < 0)
@@ -1507,7 +1584,8 @@ public class ForkJoinPool extends Abstra
     /**
      * Same idea as preJoin
      */
-    final boolean preBlock(ManagedBlocker blocker, boolean maintainParallelism){
+    final boolean preBlock(ManagedBlocker blocker,
+                           boolean maintainParallelism) {
         maintainParallelism &= maintainsParallelism;
         boolean dec = false;
         while (spareStack == null || !tryResumeSpare(dec)) {
@@ -1525,12 +1603,13 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Returns true if a spare thread appears to be needed.  If
-     * maintaining parallelism, returns true when the deficit in
+     * Returns {@code true} if a spare thread appears to be needed.
+     * If maintaining parallelism, returns true when the deficit in
      * running threads is more than the surplus of total threads, and
      * there is apparently some work to do.  This self-limiting rule
      * means that the more threads that have already been added, the
      * less parallelism we will tolerate before adding another.
+     *
      * @param counts current worker counts
      * @param maintainParallelism try to maintain parallelism
      */
@@ -1548,8 +1627,9 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Add a spare worker if lock available and no more than the
-     * expected numbers of threads exist
+     * Adds a spare worker if lock available and no more than the
+     * expected numbers of threads exist.
+     *
      * @return true if successful
      */
     private boolean tryAddSpare(int expectedCounts) {
@@ -1582,7 +1662,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Add the kth spare worker. On entry, pool counts are already
+     * Adds the kth spare worker. On entry, pool counts are already
      * adjusted to reflect addition.
      */
     private void createAndStartSpare(int k) {
@@ -1604,11 +1684,12 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Suspend calling thread w if there are excess threads.  Called
-     * only from sync.  Spares are enqueued in a Treiber stack
-     * using the same WaitQueueNodes as barriers.  They are resumed
-     * mainly in preJoin, but are also woken on pool events that
-     * require all threads to check run state.
+     * Suspends calling thread w if there are excess threads.  Called
+     * only from sync.  Spares are enqueued in a Treiber stack using
+     * the same WaitQueueNodes as barriers.  They are resumed mainly
+     * in preJoin, but are also woken on pool events that require all
+     * threads to check run state.
+     *
      * @param w the caller
      */
     private boolean suspendIfSpare(ForkJoinWorkerThread w) {
@@ -1619,7 +1700,7 @@ public class ForkJoinPool extends Abstra
                 node = new WaitQueueNode(0, w);
             if (casWorkerCounts(s, s-1)) { // representation-dependent
                 // push onto stack
-                do;while (!casSpareStack(node.next = spareStack, node));
+                do {} while (!casSpareStack(node.next = spareStack, node));
                 // block until released by resumeSpare
                 node.awaitSpareRelease();
                 return true;
@@ -1629,7 +1710,8 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Try to pop and resume a spare thread.
+     * Tries to pop and resume a spare thread.
+     *
      * @param updateCount if true, increment running count on success
      * @return true if successful
      */
@@ -1647,7 +1729,8 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Pop and resume all spare threads. Same idea as ensureSync.
+     * Pops and resumes all spare threads. Same idea as ensureSync.
+     *
      * @return true if any spares released
      */
     private boolean resumeAllSpares() {
@@ -1665,7 +1748,7 @@ public class ForkJoinPool extends Abstra
     }
 
     /**
-     * Pop and shutdown excessive spare threads. Call only while
+     * Pops and shuts down excessive spare threads. Call only while
      * holding lock. This is not guaranteed to eliminate all excess
      * threads, only those suspended as spares, which are the ones
      * unlikely to be needed in the future.
@@ -1690,41 +1773,42 @@ public class ForkJoinPool extends Abstra
     /**
      * Interface for extending managed parallelism for tasks running
      * in ForkJoinPools. A ManagedBlocker provides two methods.
-     * Method {@code isReleasable} must return true if blocking is not
-     * necessary. Method {@code block} blocks the current thread
-     * if necessary (perhaps internally invoking isReleasable before
-     * actually blocking.).
+     * Method {@code isReleasable} must return {@code true} if
+     * blocking is not necessary. Method {@code block} blocks the
+     * current thread if necessary (perhaps internally invoking
+     * {@code isReleasable} before actually blocking.).
+     *
      * <p>For example, here is a ManagedBlocker based on a
      * ReentrantLock:
-     * <pre>
-     *   class ManagedLocker implements ManagedBlocker {
-     *     final ReentrantLock lock;
-     *     boolean hasLock = false;
-     *     ManagedLocker(ReentrantLock lock) { this.lock = lock; }
-     *     public boolean block() {
-     *        if (!hasLock)
-     *           lock.lock();
-     *        return true;
-     *     }
-     *     public boolean isReleasable() {
-     *        return hasLock || (hasLock = lock.tryLock());
-     *     }
+     *  <pre> {@code
+     * class ManagedLocker implements ManagedBlocker {
+     *   final ReentrantLock lock;
+     *   boolean hasLock = false;
+     *   ManagedLocker(ReentrantLock lock) { this.lock = lock; }
+     *   public boolean block() {
+     *     if (!hasLock)
+     *       lock.lock();
+     *     return true;
      *   }
-     * </pre>
+     *   public boolean isReleasable() {
+     *     return hasLock || (hasLock = lock.tryLock());
+     *   }
+     * }}</pre>
      */
     public static interface ManagedBlocker {
         /**
          * Possibly blocks the current thread, for example waiting for
          * a lock or condition.
-         * @return true if no additional blocking is necessary (i.e.,
-         * if isReleasable would return true).
+         *
+         * @return {@code true} if no additional blocking is necessary
+         * (i.e., if isReleasable would return true)
          * @throws InterruptedException if interrupted while waiting
-         * (the method is not required to do so, but is allowed to).
+         * (the method is not required to do so, but is allowed to)
          */
         boolean block() throws InterruptedException;
 
         /**
-         * Returns true if blocking is unnecessary.
+         * Returns {@code true} if blocking is unnecessary.
          */
         boolean isReleasable();
     }
@@ -1734,36 +1818,36 @@ public class ForkJoinPool extends Abstra
      * is a ForkJoinWorkerThread, this method possibly arranges for a
      * spare thread to be activated if necessary to ensure parallelism
      * while the current thread is blocked.  If
-     * {@code maintainParallelism} is true and the pool supports
+     * {@code maintainParallelism} is {@code true} and the pool supports
      * it ({@link #getMaintainsParallelism}), this method attempts to
-     * maintain the pool's nominal parallelism. Otherwise if activates
+     * maintain the pool's nominal parallelism. Otherwise it activates
      * a thread only if necessary to avoid complete starvation. This
      * option may be preferable when blockages use timeouts, or are
      * almost always brief.
      *
      * <p> If the caller is not a ForkJoinTask, this method is behaviorally
      * equivalent to
-     * <pre>
-     *   while (!blocker.isReleasable())
-     *      if (blocker.block())
-     *         return;
-     * </pre>
+     *  <pre> {@code
+     * while (!blocker.isReleasable())
+     *   if (blocker.block())
+     *     return;
+     * }</pre>
      * If the caller is a ForkJoinTask, then the pool may first
      * be expanded to ensure parallelism, and later adjusted.
      *
      * @param blocker the blocker
-     * @param maintainParallelism if true and supported by this pool,
-     * attempt to maintain the pool's nominal parallelism; otherwise
-     * activate a thread only if necessary to avoid complete
-     * starvation.
-     * @throws InterruptedException if blocker.block did so.
+     * @param maintainParallelism if {@code true} and supported by
+     * this pool, attempt to maintain the pool's nominal parallelism;
+     * otherwise activate a thread only if necessary to avoid
+     * complete starvation.
+     * @throws InterruptedException if blocker.block did so
      */
     public static void managedBlock(ManagedBlocker blocker,
                                     boolean maintainParallelism)
         throws InterruptedException {
         Thread t = Thread.currentThread();
-        ForkJoinPool pool = (t instanceof ForkJoinWorkerThread?
-                             ((ForkJoinWorkerThread)t).pool : null);
+        ForkJoinPool pool = ((t instanceof ForkJoinWorkerThread) ?
+                             ((ForkJoinWorkerThread) t).pool : null);
         if (!blocker.isReleasable()) {
             try {
                 if (pool == null ||
@@ -1778,83 +1862,85 @@ public class ForkJoinPool extends Abstra
 
     private static void awaitBlocker(ManagedBlocker blocker)
         throws InterruptedException {
-        do;while (!blocker.isReleasable() && !blocker.block());
+        do {} while (!blocker.isReleasable() && !blocker.block());
     }
 
     // AbstractExecutorService overrides
 
     protected <T> RunnableFuture<T> newTaskFor(Runnable runnable, T value) {
-        return new AdaptedRunnable(runnable, value);
+        return new AdaptedRunnable<T>(runnable, value);
     }
 
     protected <T> RunnableFuture<T> newTaskFor(Callable<T> callable) {
-        return new AdaptedCallable(callable);
-    }
-
-
-    // Temporary Unsafe mechanics for preliminary release
-    private static Unsafe getUnsafe() throws Throwable {
-        try {
-            return Unsafe.getUnsafe();
-        } catch (SecurityException se) {
-            try {
-                return java.security.AccessController.doPrivileged
-                    (new java.security.PrivilegedExceptionAction<Unsafe>() {
-                        public Unsafe run() throws Exception {
-                            return getUnsafePrivileged();
-                        }});
-            } catch (java.security.PrivilegedActionException e) {
-                throw e.getCause();
-            }
-        }
-    }
-
-    private static Unsafe getUnsafePrivileged()
-            throws NoSuchFieldException, IllegalAccessException {
-        Field f = Unsafe.class.getDeclaredField("theUnsafe");
-        f.setAccessible(true);
-        return (Unsafe) f.get(null);
-    }
-
-    private static long fieldOffset(String fieldName)
-            throws NoSuchFieldException {
-        return _unsafe.objectFieldOffset
-            (ForkJoinPool.class.getDeclaredField(fieldName));
+        return new AdaptedCallable<T>(callable);
     }
 
-    static final Unsafe _unsafe;
-    static final long eventCountOffset;
-    static final long workerCountsOffset;
-    static final long runControlOffset;
-    static final long syncStackOffset;
-    static final long spareStackOffset;
+    // Unsafe mechanics
 
-    static {
-        try {
-            _unsafe = getUnsafe();
-            eventCountOffset = fieldOffset("eventCount");
-            workerCountsOffset = fieldOffset("workerCounts");
-            runControlOffset = fieldOffset("runControl");
-            syncStackOffset = fieldOffset("syncStack");
-            spareStackOffset = fieldOffset("spareStack");
-        } catch (Throwable e) {
-            throw new RuntimeException("Could not initialize intrinsics", e);
-        }
-    }
+    private static final sun.misc.Unsafe UNSAFE = getUnsafe();
+    private static final long eventCountOffset =
+        objectFieldOffset("eventCount", ForkJoinPool.class);
+    private static final long workerCountsOffset =
+        objectFieldOffset("workerCounts", ForkJoinPool.class);
+    private static final long runControlOffset =
+        objectFieldOffset("runControl", ForkJoinPool.class);
+    private static final long syncStackOffset =
+        objectFieldOffset("syncStack",ForkJoinPool.class);
+    private static final long spareStackOffset =
+        objectFieldOffset("spareStack", ForkJoinPool.class);
 
     private boolean casEventCount(long cmp, long val) {
-        return _unsafe.compareAndSwapLong(this, eventCountOffset, cmp, val);
+        return UNSAFE.compareAndSwapLong(this, eventCountOffset, cmp, val);
     }
     private boolean casWorkerCounts(int cmp, int val) {
-        return _unsafe.compareAndSwapInt(this, workerCountsOffset, cmp, val);
+        return UNSAFE.compareAndSwapInt(this, workerCountsOffset, cmp, val);
     }
     private boolean casRunControl(int cmp, int val) {
-        return _unsafe.compareAndSwapInt(this, runControlOffset, cmp, val);
+        return UNSAFE.compareAndSwapInt(this, runControlOffset, cmp, val);
     }
     private boolean casSpareStack(WaitQueueNode cmp, WaitQueueNode val) {
-        return _unsafe.compareAndSwapObject(this, spareStackOffset, cmp, val);
+        return UNSAFE.compareAndSwapObject(this, spareStackOffset, cmp, val);
     }
     private boolean casBarrierStack(WaitQueueNode cmp, WaitQueueNode val) {
-        return _unsafe.compareAndSwapObject(this, syncStackOffset, cmp, val);
+        return UNSAFE.compareAndSwapObject(this, syncStackOffset, cmp, val);
+    }
+
+    private static long objectFieldOffset(String field, Class<?> klazz) {
+        try {
+            return UNSAFE.objectFieldOffset(klazz.getDeclaredField(field));
+        } catch (NoSuchFieldException e) {
+            // Convert Exception to corresponding Error
+            NoSuchFieldError error = new NoSuchFieldError(field);
+            error.initCause(e);
+            throw error;
+        }
+    }
+
+    /**
+     * Returns a sun.misc.Unsafe.  Suitable for use in a 3rd party package.
+     * Replace with a simple call to Unsafe.getUnsafe when integrating
+     * into a jdk.
+     *
+     * @return a sun.misc.Unsafe
+     */
+    private static sun.misc.Unsafe getUnsafe() {
+        try {
+            return sun.misc.Unsafe.getUnsafe();
+        } catch (SecurityException se) {
+            try {
+                return java.security.AccessController.doPrivileged
+                    (new java.security
+                     .PrivilegedExceptionAction<sun.misc.Unsafe>() {
+                        public sun.misc.Unsafe run() throws Exception {
+                            java.lang.reflect.Field f = sun.misc
+                                .Unsafe.class.getDeclaredField("theUnsafe");
+                            f.setAccessible(true);
+                            return (sun.misc.Unsafe) f.get(null);
+                        }});
+            } catch (java.security.PrivilegedActionException e) {
+                throw new RuntimeException("Could not initialize intrinsics",
+                                           e.getCause());
+            }
+        }
     }
 }